xref: /dpdk/examples/vm_power_manager/channel_monitor.c (revision 0857b942113874c69dc3db5df11a828ee3cc9b6b)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <unistd.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <stdint.h>
38 #include <signal.h>
39 #include <errno.h>
40 #include <string.h>
41 #include <sys/types.h>
42 #include <sys/epoll.h>
43 #include <sys/queue.h>
44 
45 #include <rte_log.h>
46 #include <rte_memory.h>
47 #include <rte_malloc.h>
48 #include <rte_atomic.h>
49 
50 
51 #include "channel_monitor.h"
52 #include "channel_commands.h"
53 #include "channel_manager.h"
54 #include "power_manager.h"
55 
56 #define RTE_LOGTYPE_CHANNEL_MONITOR RTE_LOGTYPE_USER1
57 
58 #define MAX_EVENTS 256
59 
60 
61 static volatile unsigned run_loop = 1;
62 static int global_event_fd;
63 static struct epoll_event *global_events_list;
64 
65 void channel_monitor_exit(void)
66 {
67 	run_loop = 0;
68 	rte_free(global_events_list);
69 }
70 
71 static int
72 process_request(struct channel_packet *pkt, struct channel_info *chan_info)
73 {
74 	uint64_t core_mask;
75 
76 	if (chan_info == NULL)
77 		return -1;
78 
79 	if (rte_atomic32_cmpset(&(chan_info->status), CHANNEL_MGR_CHANNEL_CONNECTED,
80 			CHANNEL_MGR_CHANNEL_PROCESSING) == 0)
81 		return -1;
82 
83 	if (pkt->command == CPU_POWER) {
84 		core_mask = get_pcpus_mask(chan_info, pkt->resource_id);
85 		if (core_mask == 0) {
86 			RTE_LOG(ERR, CHANNEL_MONITOR, "Error get physical CPU mask for "
87 				"channel '%s' using vCPU(%u)\n", chan_info->channel_path,
88 				(unsigned)pkt->unit);
89 			return -1;
90 		}
91 		if (__builtin_popcountll(core_mask) == 1) {
92 
93 			unsigned core_num = __builtin_ffsll(core_mask) - 1;
94 
95 			switch (pkt->unit) {
96 			case(CPU_POWER_SCALE_MIN):
97 					power_manager_scale_core_min(core_num);
98 			break;
99 			case(CPU_POWER_SCALE_MAX):
100 					power_manager_scale_core_max(core_num);
101 			break;
102 			case(CPU_POWER_SCALE_DOWN):
103 					power_manager_scale_core_down(core_num);
104 			break;
105 			case(CPU_POWER_SCALE_UP):
106 					power_manager_scale_core_up(core_num);
107 			break;
108 			default:
109 				break;
110 			}
111 		} else {
112 			switch (pkt->unit) {
113 			case(CPU_POWER_SCALE_MIN):
114 					power_manager_scale_mask_min(core_mask);
115 			break;
116 			case(CPU_POWER_SCALE_MAX):
117 					power_manager_scale_mask_max(core_mask);
118 			break;
119 			case(CPU_POWER_SCALE_DOWN):
120 					power_manager_scale_mask_down(core_mask);
121 			break;
122 			case(CPU_POWER_SCALE_UP):
123 					power_manager_scale_mask_up(core_mask);
124 			break;
125 			default:
126 				break;
127 			}
128 
129 		}
130 	}
131 	/* Return is not checked as channel status may have been set to DISABLED
132 	 * from management thread
133 	 */
134 	rte_atomic32_cmpset(&(chan_info->status), CHANNEL_MGR_CHANNEL_PROCESSING,
135 			CHANNEL_MGR_CHANNEL_CONNECTED);
136 	return 0;
137 
138 }
139 
140 int
141 add_channel_to_monitor(struct channel_info **chan_info)
142 {
143 	struct channel_info *info = *chan_info;
144 	struct epoll_event event;
145 
146 	event.events = EPOLLIN;
147 	event.data.ptr = info;
148 	if (epoll_ctl(global_event_fd, EPOLL_CTL_ADD, info->fd, &event) < 0) {
149 		RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to add channel '%s' "
150 				"to epoll\n", info->channel_path);
151 		return -1;
152 	}
153 	return 0;
154 }
155 
156 int
157 remove_channel_from_monitor(struct channel_info *chan_info)
158 {
159 	if (epoll_ctl(global_event_fd, EPOLL_CTL_DEL, chan_info->fd, NULL) < 0) {
160 		RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to remove channel '%s' "
161 				"from epoll\n", chan_info->channel_path);
162 		return -1;
163 	}
164 	return 0;
165 }
166 
167 int
168 channel_monitor_init(void)
169 {
170 	global_event_fd = epoll_create1(0);
171 	if (global_event_fd == 0) {
172 		RTE_LOG(ERR, CHANNEL_MONITOR, "Error creating epoll context with "
173 				"error %s\n", strerror(errno));
174 		return -1;
175 	}
176 	global_events_list = rte_malloc("epoll_events", sizeof(*global_events_list)
177 			* MAX_EVENTS, RTE_CACHE_LINE_SIZE);
178 	if (global_events_list == NULL) {
179 		RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to rte_malloc for "
180 				"epoll events\n");
181 		return -1;
182 	}
183 	return 0;
184 }
185 
186 void
187 run_channel_monitor(void)
188 {
189 	while (run_loop) {
190 		int n_events, i;
191 
192 		n_events = epoll_wait(global_event_fd, global_events_list,
193 				MAX_EVENTS, 1);
194 		if (!run_loop)
195 			break;
196 		for (i = 0; i < n_events; i++) {
197 			struct channel_info *chan_info = (struct channel_info *)
198 					global_events_list[i].data.ptr;
199 			if ((global_events_list[i].events & EPOLLERR) ||
200 					(global_events_list[i].events & EPOLLHUP)) {
201 				RTE_LOG(DEBUG, CHANNEL_MONITOR, "Remote closed connection for "
202 						"channel '%s'\n", chan_info->channel_path);
203 				remove_channel(&chan_info);
204 				continue;
205 			}
206 			if (global_events_list[i].events & EPOLLIN) {
207 
208 				int n_bytes, err = 0;
209 				struct channel_packet pkt;
210 				void *buffer = &pkt;
211 				int buffer_len = sizeof(pkt);
212 
213 				while (buffer_len > 0) {
214 					n_bytes = read(chan_info->fd, buffer, buffer_len);
215 					if (n_bytes == buffer_len)
216 						break;
217 					if (n_bytes == -1) {
218 						err = errno;
219 						RTE_LOG(DEBUG, CHANNEL_MONITOR, "Received error on "
220 								"channel '%s' read: %s\n",
221 								chan_info->channel_path, strerror(err));
222 						remove_channel(&chan_info);
223 						break;
224 					}
225 					buffer = (char *)buffer + n_bytes;
226 					buffer_len -= n_bytes;
227 				}
228 				if (!err)
229 					process_request(&pkt, chan_info);
230 			}
231 		}
232 	}
233 }
234